As one of the procedures for manufacturing a semiconductor device, there may be a procedure of forming a thin film on a substrate in a process chamber by supplying a precursor gas or a reaction gas to the substrate. During this film forming process, deposits such as a thin film are adhered to an interior of the process chamber. Therefore, a cleaning process of removing the deposits adhered to the interior of the process chamber may be performed by supplying a cleaning gas into the process chamber and exhausting the cleaning gas from the process chamber through an exhaust pipe after the film forming process.
However, in some cases, during the above-mentioned cleaning process, an inner wall of the exhaust pipe may be corroded.